Moving objects in digital video displayed on a hold-type display device, such as a liquid crystal display (LCD), can appear blurry to an observer. The perceived blur is caused in part by the relatively slow “LC response” of the liquid crystal cells. When compared with an impulse-type device such as a cathode ray tube (CRT) device, for example, an LCD device has a much slower brightness transition response time. The perceived blur is also caused in part by prolonged light emission inherent in the sample-and-hold driving technique commonly employed by LCD devices, which results in formation of after-images on the human retina. These after-images produce a blurred visual perception as a moving object is being observed in the video sequence.
For example, as an input video sequence is input to an LCD device, each digital video image (alternatively referred to as a frame), from the input video sequence is displayed and sustained on the LCD device for one frame interval. While viewing an object in motion in a scene, the human eyes actively track the object with smooth pursuit eye movement so as to generate a stabilized image on the human retina. The combination of the LCD device and the tracking behavior of the human visual system, however, results in a spatial low pass filtering effect, i.e., a blur effect.
Numerous methods have been proposed to compensate for motion blur. One method is to insert a black frame between each pair of frames in a frame sequence. This method essentially simulates an impulse display, which does not suffer perceived motion blur problems. However, an overall reduction in brightness results from implementation of this method. Alternatively, video pre-processing may be applied to frames of the digital video sequence prior to display on the hold-type device. Video pre-processing methods that presently exist have certain drawbacks, however, such as high computational cost, loss of resolution, or artifacts such as false motion edges and frame juddering.